Radial arms of radial arm saws have to be strong and sufficiently stable to carry in cantilever manner the suspended weight of a circular saw unit, including an electric motor for driving the saw blade, and at the same time allow precise positioning of the saw blade when cutting. This has resulted in such radial arms being robustly manufactured from steel. Although this is generally satisfactory for a permanently positioned radial arm saw, it substantially adds to the weight of the radial arm saw. This weight is a disadvantage during transportation of the machine, and is particularly so with units that are intended to be portable.
Further, the formation of guide means in these radial arms, for movement of the power tool unit therealong, can involve relatively costly precision machining.